00:02
Okay, so we're going to be solving for systems of equations today, but instead of being explicitly given two equations to solve for, we're given a word problem, which means we first have to read the problem, understand the question, identify the variables, write the equations, and then solve the equations.
00:18
So let's start.
00:19
So here we are given a married couple, a wife and a husband.
00:24
So those are variables.
00:25
So let's name those two variables.
00:28
So the variables are husband and wife.
00:34
Let's assign the husband to be x and the wife to be y.
00:40
So it says they together earn $75 ,000, which means our first equation is going to be x plus y equals $75 ,000.
00:52
All right.
00:54
The husband earns 15 ,000 more than five times his wife earns.
00:58
Okay.
00:58
The husband is x.
01:00
That means x is going to be 15 ,000 more than five times what the wife earns.
01:04
So 5y plus 15 ,000.
01:09
We want to know what the wife earns.
01:11
So we want to solve for y.
01:14
Okay.
01:15
Whenever i'm solving for equations, i like my variables to be on one side and my constants to be on one side.
01:21
We have a 5 y here on this side, so we're going to bring it over here.
01:25
So let's do that first.
01:26
So let's just rewrite the first equation...